TipcSrvConnSubjectSetSubscribeLb

Name

TipcSrvConnSubjectSetSubscribeLb — start or stop subscribing to a subject, with or without load balancing

Synopsis

T_BOOL TipcSrvConnSubjectSetSubscribeLb(srv, subject, subscribe_status, 
lb_status) 
T_IPC_SRV srv; 
T_STR subject; 
T_BOOL subscribe_status; 
T_BOOL lb_status; 

Arguments

srv — connection handle to RTserver

subject — name of the subject to set subscribe status for

subscribe_status — subscribe status

lb_status — load balancing status

Return Values

TRUE if the subscribe status of the subject was successfully set, FALSE otherwise.

Diagnostics

If TipcSrvConnSubjectSetSubscribeLb fails, it returns FALSE and sets the global SmartSockets error number to one of:

Description

TipcSrvConnSubjectGetSubscribeLb and TipcSrvConnSubjectSetSubscribeLb are variants of TipcSrvConnSubjectGetSubscribe and TipcSrvConnSubjectSetSubscribe that include load balancing control.

TipcSrvConnSubjectSetSubscribeLb sets whether or not this RTclient is subscribing to a subject, with or without load balancing. The subscribe status controls whether or not the RTclient receives messages published (sent) to that subject. If the subscribe status of subject is TRUE, then the RTclient receives messages with subject as their destination that are sent to RTserver. To determine if an RTclient is subscribing to a subject, including load balancing information, use TipcSrvConnSubjectGetSubscribeLb. If the load balancing status of subject is TRUE, then the RTclient is part of the load balancing calculation; otherwise the RTclient overrides load balancing and always receives the messages regardless of whether or not the message was published with load balancing.

TipcSrvConnSubjectSetSubscribeLb may attempt to automatically create a connection to RTserver. If RTclient has a warm connection to RTserver, TipcSrvConnSubjectSetSubscribeLb sets the subscribe status of the subject as if the RTclient were still connected to RTserver. See TipcSrvConnOpen for more information on automatic creation of connections and warm connections to RTserver.

Caution

TipcSrvConnSubjectSetSubscribeLb sends a SUBJECT_SET_SUBSCRIBE message to RTserver, but does not explicitly flush the message. See TipcSrvConnGetAutoFlushSize for more information on message buffering.

See Also

TipcMonClientSubscribeSetWatch, TipcMonSubjectSubscribeSetWatch, TipcSrvConnSubjectGetSubscribeLb, TipcSrvConnSubjectSetSubscribe

Examples

This example uses TipcSrvConnSubjectSetSubscribeLb to start subscribing to the subject /system/thermal and override load balancing so that this RTclient receives all messages published to the thermal subject regardless of whether or not they were published with load balancing:

if (!TipcSrvConnSubjectSetSubscribeLb(srv, "/system/thermal", 
                                      TRUE, FALSE)) { 
  return;  /* error */ 
}